An Open Source Boating Autopilot With Some Custom Tweaks

December 17, 2019 by Lewin Day 11 Comments

Piloting a boat is all well and good, but can get dull when you’d rather be reclining on the deck with a cold beverage in hand. For [Timo Birnschein], this simply wouldn’t do. He began to gather parts to put together an autopilot to keep his boat on the straight and narrow.

The build is based around OpenPlotter, which uses a battery of marine-ready software to handle routing charts, autopiloting, and providing a compass heading for navigation. Naturally, it all runs on a Raspberry Pi. In combination with PyPilot, it can be used to let the vessel drive itself around a series of waypoints, allowing you to soak up the atmosphere on the water without having to constantly steer the craft.

[Timo] ran into some issues, however, with the hardware side of things. Existing implementations for motor control to drive the rudder weren’t quite cutting it, so the system was reworked to run with a robust H-bridge and some fresh Arduino code. This was combined with a custom rudder sensor built with a potentiometer and some 3D printed gears. Future work aims to double up the rudder sensors for redundancy, something we should all consider at times.

Overall, the system is starting to come together, and [Timo]’s enjoying letting his boat think for itself. He notes that it’s very important to keep an eye on the boat while operating in this condition, lest it veer off course – many a boat has been lost this way. We’re always supporters of a mature attitude towards autonomous vehicle operations!

Tidy Board Rework Uses Flex PCBs, No Wires

December 17, 2019 by Donald Papp 26 Comments

PCB rework for the purpose of fixing unfortunate design problems tends to involve certain things: thin wires (probably blue) to taped or glued down components, and maybe some areas of scraped-off soldermask. What are not usually involved are flexible PCBs, but [Paul Bryson] shows us exactly how flex PCBs can be used to pull off tricky rework tasks.

It all started when [Paul] had a run of expensive PCBs with a repeated error; a design mistake that occurred in several places in the board. Fixing with a bunch of flying wires leading to some glued-on components just wasn’t his idea of tidy. A more attractive fix would be to make a small PCB that could be soldered in place of several of the ICs on the board, but this idea had a few problems: the space available into which to cram a fix wasn’t always the same, and the footprints of the ICs to be replaced were too small to accommodate a PCB with castellated mounting holes as pads anyway.

It’s about then that he got a visit from the Good Idea Fairy, recalling that fab houses have recently offered “flex” PCBs at a reasonable cost. By mounting the replacement parts on a flex PCB, the board-level connection could reside on the other end of an extension. Solder one end directly to the board, and the whole flexible thing could be bent around or under on a case-by-case basis, and secured in whatever way made sense. Soldering the pads of the flex board to the pads on the PCB was a bit tricky, but easy enough to pull off reliably with a bit of practice. A bonus was that the flex PCB is transparent, so solder bridges are easy to spot. He even mocked up a solution for QFP packages that allows easy pin access.

Flex PCBs being available to hobbyists and individuals brings out fresh ideas and new twists on old ones, which is why we held a Flexible PCB Design Contest earlier this year. Repairs were definitely represented as applications, but not to the extent that [Paul] has shown. Nice work!

A Nixie Radio Clock Fit For A Victorian Mad Scientist

December 17, 2019 by Gerrit Coetzee 11 Comments

[Ioszelos] built a nixie clock with a dizzying array of features.

Do you ever wish that you could log in to your clock from your phone and turn off your TV? We assume that [Ioszelos] did. The clock can also play MP3s and stream radio stations. It can record the indoor temperature, humidity, and barometric pressure. Did we mention it’s an FM radio too? We’re not sure, but we wouldn’t be surprised if there was a faucet hiding somewhere on the contraption.

A team effort shared between an ESP32 and Mega 2560 run the Rube Goldberg-like show. Custom boards were spun up to provide the control and voltages needed for the nixie tubes. The clock is constructed from machined plates and 3D printed files.

It all comes together in a steampunk reminiscent assembly. The glow from the RGB leds and nixie tubes combine to make an interesting visual effect. We’ve certainly never seen a clock quite like it before.

Linux Fu: Stupid SSH Tricks

December 17, 2019 by Al Williams 52 Comments

If you connect to remote computers over the Internet, it is a pretty good chance you use some form of SSH or secure shell. On Linux or Unix you’ll use the ssh command. Same goes for Linux-like environments on Windows like Cygwin or WSL. For native Windows, you might be using Putty. In its simplest form, ssh is just a terminal program that talks to a server using an encrypted connection. We think it is very hard to eavesdrop on anyone communicating with a remote computer via ssh.

There are several tricks for using ssh — some are pretty straightforward and some are things you might not think of as being in the domain of a terminal program. You probably know that ssh can copy files securely, and there are easy and hard ways to set up logging in with no password.

However, you can also mount a remote filesystem via ssh (actually, there are several ways to do that). You can use ssh to securely browse the web in your favorite browser, or even use it to tunnel specific traffic by port or even use it as a makeshift VPN. In fact, there’s so much ground to cover that this won’t be the last Linux Fu to talk about ssh. But enough setup, let’s get to the tricks.

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This Machine Is Poised To Join The Fight Against Cancer

December 17, 2019 by Kristina Panos 40 Comments

Can you imagine a near future where your family doctor can effectively prick your finger and test you for a dozen or so types of cancer? Currently, cancer detection is a time-consuming and expensive process. Existing methods of screening for cancer usually involve taking a whole lot of blood and running tests that cost thousands of dollars. But Toshiba has created a cancer-detecting machine that sounds like something straight out of science fiction.

A researcher tests the Toray method. Image via Nikkei Asian Review

The machine is about the size of a small office copier, and it looks like one, too. But this small machine can do some powerful tricks. Toshiba claims that the machine can detect 13 types of cancer from a single drop of blood with 99% accuracy. What’s more impressive is that it can do this under two hours, as opposed to days or weeks depending on laboratory backlog. Most importantly, they are aiming to do this entire battery of tests for about $180. Ideally, this machine will do everything that current blood cancer detection equipment does, just better, faster, and with fewer resources.

Some of the cancers the machine can test for have been previously difficult to detect, like ovarian, pancreatic, and esophageal cancer. But this machine can screen for all three of these — great news for early detection of these ravaging cancers — as well as breast, prostate, gastric, colon, liver, biliary tract, bladder, lung, brain, and sarcoma. The only catch is that the machine can’t pinpoint which cancer exactly, it only knows if microRNA one or more of the 13 came up.

Image source: Toshiba Corporate Reserach Center

So, how does it work? Cancer cells secrete certain types of microRNA into the bloodstream that healthy cells don’t. The machine works by assessing the different types of microRNA that show up in the sample drop, and studying their concentrations. Their work builds on that of Toray Industries, who announced earlier this year that they had made a cancer-detection chip based on microRNA accumulation that is 95% accurate. Development of this chip follows on the heels of research that finds testing for microRNA in bloodwork has the potential to detect cancers in earlier stages, and in some cases like for bowel cancer, with a much less invasive testing procedure.

Toshiba, in partnership with the National Cancer Center Research Institute and Tokyo Medical University will conduct a trial of the machine next year. If the trial is successful, they hope to commercialize it soon after.

Humongous 3D Printer Produces Boat And Challenges

December 17, 2019 by Danie Conradie 27 Comments

We’ve seen some pretty big polymer 3D printers, but nothing quite as big as the University of Maine’s 3D printer with a 22,000 ft³ (623 m³) build volume. It holds the Guinness World Record for the largest polymer 3D printer, and with that size comes some interesting challenges and advantages.

You might have already seen the video of it printing an entire patrol boat hull in a single piece, and would have noticed how it printed at a 45° angle. Due to the sheer weight and thermal mass of the print bead, it cannot bridge more than an inch, since it’ll just sag. A 45° overhang angle is about all it can manage, but since the layers can be tilted at that angle, it ends up being able to print horizontal roofs with no support. A 10 mm nozzle is used and the extruded line ends up being 12.5 mm in diameter with a 5 mm layer height. The boat mentioned above was printed with carbon ABS, but it can reportedly use almost any thermoplastic. It looks like the extruder is a screw extruder from an injection moulding machine, and is likely fed with pellets, which is a lot more practical than filament at this scale. Check out the video below by [Paul Bussiere] who works in the Advanced Structures & Composites Center at the University. He also does a very interesting interview with his boss, [James M. Anderson].

The 45° layer angle is very similar to how some infinite build volume 3D printers work. For something more within the reach of the average hacker, check out the tool changing Jubilee.
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Modulated Pilot Lights Anchor AR To Real World

December 17, 2019 by Dan Maloney 26 Comments

We’re going to go out on a limb here and say that wherever you are now, a quick glance around will probably reveal at least one LED. They’re everywhere – we can spot a quick half dozen from our desk, mostly acting as pilot lights and room lighting. In those contexts, LEDs are pretty mundane. But what if a little more flash could be added to the LEDs of the world – literally?

That’s the idea behind LightAnchors, which bills itself as a “spatially-anchored augmented reality interface.” LightAnchors comes from work at [Chris Harrison]’s lab at Carnegie Mellon University which seeks new ways to interface with computers, and leverages the ubiquity of LED point sources and the high-speed cameras on today’s smartphones. LightAnchors are basically beacons of digitally encoded data that a smartphone can sense and decode. The target LED is modulated using amplitude-shift keying and each packet contains a data payload and parity bits along with a pre- and post-amble sequence. Software on the phone uses the camera to isolate the point source, track it, and pull the data out of it, which is used to create an overlay on the scene. The video below shows a number of applications, ranging from displaying guest login credentials through the pilot lights on a router to modulating the headlights of a rideshare vehicle so the next fare can find the right car.

An academic paper (PDF link) goes into greater depth on the protocol, and demo Arduino code for creating LightAnchors is thoughtfully provided. It strikes us that the two main hurdles to adoption of LightAnchors would be convincing device manufacturers to support them, and advertising the fact that what looks like a pilot light might actually be something more, but the idea sure beats fixed markers for AR tracking.

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